TOI explains: How Nisar was built - why it'll take 90 days before any data comes in
NEW DELHI: The India-US Earth observation satellite, Nasa-Isro Synthetic Aperture Radar (Nisar), is set for launch on July 30 from Isro's spaceport in Sriharikota aboard the GSLV-F16 rocket.
But the mission's real work begins after it enters orbit. Over the next several weeks, the satellite will go through a carefully sequenced set of actions before it starts sending data. In all, Nisar will need at least 90 days to enter its 'science phase'.
How Nisar was built
Before we get to what happens after launch, here's how the satellite came together: Nisar is the result of nearly a decade of collaboration between Isro and Nasa. Over 8–10 years, both agencies separately developed and tested key systems, which were then brought together into one observatory.
The core radar payload was built in parts — Isro developed the S-band synthetic aperture radar (SAR), and Nasa's Jet Propulsion Laboratory (JPL) built the L-band SAR. These were integrated into a shared structure called the Integrated Radar Instrument Structure (IRIS).
Assembly of IRIS and other payload elements took place at JPL. The structure was then shipped to Isro, which had in parallel developed the satellite's mainframe at the UR Rao Satellite Centre (URSC) in Bengaluru.
by Taboola
by Taboola
Sponsored Links
Sponsored Links
Promoted Links
Promoted Links
You May Like
Brother Donates Kidney To Save Sister's Life. One Year Later, He Says, I Wish I Never Did It, When This Happens
Daily Sport X
Undo
Isro then carried out the final assembly, integration and testing of the complete satellite.
And now that the satellite is ready for launch, let's look at what will happen in the starting Wednesday:
Phase 1: Launch
At 5.40pm on Wednesday (July 30), the GSLV-F16 rocket will place the 2.8-tonne satellite into a Sun-synchronous polar orbit. This means the satellite will pass over the same part of Earth at roughly the same local solar time every day — ideal for tracking changes on the surface.
Phase 2: Deployment (Post-launch Days 10-18)
Nisar carries a massive 12-metre-wide mesh reflector, which acts as a radar antenna. Since it is too large to launch fully open, it will be folded and stowed during launch and then deployed in space using a complex multistage boom system.
The process begins on the 10th day from launch — 'Mission Day 10' which becomes 'Deploy Day 1'. Here's how the deployment unfolds: On Deploy Day 1 (DD-1), engineers initiate pre-deployment checks and unlock six 'launch restraints' that keep the system secure during launch.
Two more restraints are released, and the first hinge (called the 'wrist hinge') is activated on DD-2. This starts the unfolding motion of the boom.
On DD-3, the shoulder hinge is extended, swinging the boom further outward and on DD-4, the elbow hinge opens, continuing the arm-like movement. The root hinge is deployed on DD-5, bringing the boom to full extension, and on DD-6, a pause is built into the schedule to allow for analysis and verification of earlier steps.
And, DD-7 will be a buffer or 'margin' day in case any delays or issues need to be addressed. Once this is through, on DD-8, the satellite performs a 'yaw manoeuvre' (rotation) to correctly orient itself, and then finally opens the circular radar reflector. This slow, deliberate sequence ensures the delicate boom and antenna unfold without damage or misalignment, and paves the way for the next phase.
Phase 3: Commissioning
After deployment and until the 90th day from launch, all systems are checked and calibrated.
This includes the satellite's mainframe, radar electronics, and onboard instruments developed by both Isro and JPL.
Phase 4: Science Ops
Once fully operational, Nisar will begin capturing data across both L-band and S-band frequencies. The satellite will observe ground movement, ice sheets, forests and land use — feeding data to researchers worldwide. Regular manoeuvres will keep it in position, and a pre-coordinated observation plan will guide its workload until the end of its mission life.
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
The Print
an hour ago
- The Print
Born out of bitter Kargil lesson, NavIC was India's answer to GPS. Why it's still struggling to take off
Developed by the Indian Space Research Organisation (ISRO), the navigation system appears to be slipping from its initial promise. It had become imperative for India to invest in the technology back in 1999, when its request to access GPS data for enemy locations in the Kargil region was denied. The incident prompted the government to press for a strategically designed home-grown navigation system. Only four of 11 NavIC satellites are currently in use with the capability to provide position, navigation and timing services, Union Minister for Science and Technology Jitendra Singh told the Lok Sabha last month. The remaining four are being used for one-way message broadcast, one has been decommissioned, and two could not reach their intended orbit. New Delhi: India's satellite navigation system, the answer to US' GPS network, was built at a cost of $525 million with the aim of weaning the country from dependence on foreign powers. It was a bitter lesson learned during the Kargil War in 1999. But, nearly 26 years after it was conceived, India is still struggling to bring a functional version of Navigation with Indian Constellation or NavIC to the market. But since then, something or the other has been going wrong for India's NavIC which is yet to be fully functional regionally. 'Too much is riding on it and we cannot abandon it,' Ajey Lele, deputy director general at Manohar Parrikar Institute for Defence Studies and Analyses (MP-IDSA), told ThePrint. Adding, 'We initially faced issues with the atomic clocks from Europe, after which India started making its own atomic clocks. Then we faced issues with ground equipment. And finally, we recently had a failed mission where the satellite could not be placed in orbit. Things have been going wrong, but we cannot give up.' Currently, at least five countries have their own fully operational navigation systems—US' GPS, Russia's GLONASS, European Union's Galileo, China's BeiDou and Japan's QZSS. 'NavIC will be crucial in advancing India's defence capabilities, identifying enemy locations up to 1,500 km radius around India's borders,' former ISRO chief A.S. Kiran Kumar told ThePrint. He was at the helm when the space agency was shaping the Indian Regional Navigation Satellite System (IRNSS), whose next generation series is known as NavIC. 'The service covers the entire Indian region and also the region extending up to 1,500 km around India on dual frequencies in L5 and S bands,' a senior ISRO scientist said. L5 and S bands are radiofrequency bands used in satellite navigation communication. Such precision will help ensure accuracy of more than 20 metres in any weather condition. Also Read: DRDO eyes persistent high-altitude surveillance edge as Stratospheric Airship soars in maiden trial Setbacks and revival plans With IRNSS, the plan was to first develop the system on a regional scale that would operate only within and till a certain radius around the country's boundary. The NavIC now is meant to be operational within and up to 1,500 km radius of India but is envisioned to be a global satellite navigation system in the future, on par with GPS, Galileo and BeiDou. The first satellite (IRNSS 1A) was sent up on 1 July, 2013. In the following missions, IRNSS 1B, 1C, ID, IE, 1F, 1G, 1H, 1I, 1J, and 1K were launched. Speaking to ThePrint, a senior ISRO scientist said that currently, 1B, 1F, 1I and 1J satellites are fully operational. 1C is partially functional. 'From the next generation navigation satellites, which come under the NVS series, 1J is operational. 1K, now known as NVS-02 (launched this year), was not successful,' he said. NavIC faced one of its biggest setbacks earlier this year with the 'partial failure' of the NVS-02 mission. Early this year, ISRO launched the mission (also incidentally the 100th mission by the space agency) from Sriharikota to place the second navigation satellite under the NavIC series into a geosynchronous transfer orbit. But it could not be placed successfully. This was not the first hurdle for India's navigation satellite ambitions. In 2016, Kiran Kumar had announced that atomic clocks on IRNSS 1A had become dysfunctional. He, however, said that this did not have an impact on the overall functioning of the navigation system. At the time, the space agency stressed that the remaining six satellites in orbit were functional, but admitted that some hardware issues had been detected in the rubidium atomic clocks in some of them. Unfortunately, IRNSS 1H satellite, launched on 31 August, 2017, to replace 1A, could also not be inserted into the desired orbit. According to ISRO, a heat shield, which protects the satellite, could not be detached on time during the launch. ISRO is now banking on a series of planned missions to resuscitate NavIC. These include placement of the next set of satellites, NVS-03, NVS-04 and NVS-05, in space to boost the navigation network and bridge the gap set by the current non-functional ones. 'NVS-03 is planned to be launched by the end of 2025. Subsequently, with a gap of six months, NVS-04 and NVS-05 will be launched,' Jitendra Singh said in his Lok Sabha response. ISRO chairperson, V. Narayanan, told ThePrint last week that NVS-03 and NVS-04 are likely to take flight by the end of this year, and NVS-05 would likely launch in 2026. 'No mission is foolproof. There is always some chance of failure. NavIC is functional, but we will improve its functioning with more satellites in the coming years,' he said. NavIC-compatible phones In 2022, the government had directed major phone manufacturers to design NavIC-compatible phones for India, but there was major pushback from the industry. The government said that by 1 January, 2023, all phone models for release in India should support NavIC, stressing that the deadline was not 'hard and fast'. Phone companies said that their production costs would surge significantly with this directive. However, between 2023 and 2025, new models of the most popular phones, such as those released by Apple, Oppo, Xiaomi, OnePlus, etc, are NavIC compatible. The government has since issued repeated directives to mobile phone manufacturers to make devices compatible with NavIC. NavIC's potential does not stop with a civilian navigation system or for defence and security purposes. For civilian use, NavIC will be able to do anything that a GPS or GLONASS can, according to its mission document. Once NavIC is fully functional, anyone with a phone designed for India, within 1,500 km radius of the Indian border, would be able to access the navigation system. 'A lot of the newer phone models are already compatible with NavIC. It is currently developed as a regional navigation system, but we will be able to expand it as a global system as we get more satellites up,' Kumar told ThePrint. (Edited by Nida Fatima Siddiqui) Also Read: India will soon have its own satellites to monitor spy satellites. How the technology works
NDTV
2 hours ago
- NDTV
Why August's Moon Is Called Sturgeon Moon: Know Its Significance
The Sturgeon Full Moon is a traditional name given to August's full moon. The name represents the abundance of sturgeon fish in the Great Lakes region of North America during this time of year, according to TimeandDate. The lake sturgeon is a remarkable fish which can live up to 55 years (males) or 150 years (females). It can grow over 2 meters long and weigh around 90 kg. "The name Sturgeon Moon comes from the giant lake sturgeon of the Great Lakes and Lake Champlain; this native freshwater fish was readily caught during this part of summer and an important food staple for Native Americans who lived in the region. At one time, the lake sturgeon was quite abundant in late summer, though they are rarer today," according to The Old Farmer's Almanac. The Center for Native American Studies stated that it's called the Wild Rice Moon by the Anishinaabe people. According to NASA, it is known as the Green Corn and Grain Moon elsewhere in North America. This full moon is also known as the Corn Moon, Lynx Moon or Lightning Moon in different cultures. In Hindu traditions, it marks the festival of Raksha Bandhan, which celebrates the bond between brothers and sisters. Sturgeon Moon 2025 Facts Sturgeon Moon 2025 Date and Visibility: This year, the Sturgeon Moon will peak on August 9 at 07:54 UTC. The Moon will appear full for about three days, from August 8 to August 10. It will be visible in the eastern sky at sunset and in the western sky before sunrise. Sturgeon Moon 2025 Planetary Alignment: On August 9, Venus and Jupiter will appear close together in the eastern pre-dawn sky, creating a rare celestial event. The Moon will make a close pass to Saturn and Neptune on August 12, although only Saturn will be visible to the naked eye. Saturn will rise at 9:56 pm (EDT) on August 8 and will be visible in the constellation Pisces.
India Today
3 hours ago
- India Today
Nasa astronaut Butch Willmore, stuck with Sunita Williams in space, retires
After an illustrious 25-year career at Nasa, veteran astronaut and test pilot Butch Wilmore has officially known for his extensive time in space and pioneering missions, leaves behind a remarkable legacy of dedication and achievement in human space from Tennessee, Wilmore holds a bachelor's and master's degree in electrical engineering from Tennessee Technological University, along with a master's degree in aviation systems from the University of His distinguished service as a US Navy captain saw him flying tactical aircraft during both peacetime and combat operations aboard four aircraft carriers. A graduate of the US Naval Test Pilot School, he was selected as a Nasa astronaut in 2000. Astronaut Butch Willmore with Sunita Williams in space. (Photo: Nasa) Reflecting on Wilmore's career, Steve Koerner, acting director of Nasa's Johnson Space Center, praised his commitment: 'Butch's dedication to Nasa's mission and human space exploration is truly exemplary. His lasting legacy will inspire future explorers and the nation for generations.'Throughout his tenure at Nasa, Wilmore flew on four different spacecraft: the Space Shuttle Atlantis, Russia's Soyuz capsule, Boeing's Starliner, and the SpaceX Dragon. Over the course of his missions, he accumulated an impressive 464 days in space and conducted five spacewalks totaling 32 hours outside the International Space Station (ISS).Wilmore's most recent mission saw him launch aboard Boeing's Starliner on June 5, 2024, for its first crewed flight test. While aboard the ISS, he performed critical tasks including a spacewalk to remove a radio frequency group antenna assembly and collecting samples from the Destiny laboratory and Quest airlock. Fellow astronaut Joe Acaba noted, 'Butch exemplifies the technical excellence required of an astronaut, inspiring all of us with his adaptability and steadfast mission focus.'In his own words, Wilmore shared a profound reflection on his journey: 'From an early age, my curiosity about the cosmos drove me to explore the skies and beyond. Even as I ventured into space, I remained connected to the beauty of Earth, seeing the intricate design of creation woven between the stars and life at home.'As Butch Wilmore steps into retirement, his contributions to spaceflight and exploration continue to influence Nasa's mission and inspire future generations of astronauts.- EndsMust Watch
